16.88 (a) What are the drain currents in M1 and M2 in the reference in Fig. P16.88 if R = 4.2 kΩ and VDD = VSS = 5 V? Use K’n = 25 µA/V2 , VTN = 0.75 V, K’p = 10 µA/V2 , and VTP = −0.75 V. Assume γ = 0 and λ = 0 for both transistor types. (b) Repeat for λm = 0.6 V0.5 and λp = 0.5 V0.5 (c) What is the temperature coefficient (TC) of current ID2 in the reference in Fig. 16.27 if mobility varies as T−2.4 and resistor R has a TC of −2000 ppm/◦C?
For the two-stage OTA below, assume that Iref = 50 μA and that all transistors are designed for |Veff|= 0.2 V. Assume: |Vt|= 0.5 V for all devices, Vdd = 3 V, M5 and M7 are 2X larger than M8, λ = 0.2V-1. 1. Calculate the total power consumption of this OTA. 2. Complete the table below for the small-signal parameters of all transistors. Transistors Ids Veff gm gds ro μf 3. What is the gain of this OTA in dB? 4. What is the CMRR of this OTA in dB? 5. What is the common-mode input range of the circuit? 6. What is the output swing of this OTA? 7. Assume that this OTA has parasitic capacitances C1 = C2 = 100fF, where C1 is the total shunt capacitance at output of stage 1 and C2 is the same for stage 2. What value of Cc is needed to set the gain-bandwidth product equal to the second-pole location (resulting in 45-deg phase margin)? 8. For this value of Cc, calculate the GBW (in MHz, careful of the 2π ) and slew rate (in V/us), where slew rate is defined as 9. What value of RZ is needed to set the zero location to the LHP at 1.7X the GBW value? 10. For the values you have selected in Table 1, will this OTA have any systematic offset? Why or why not?
Consider the PMOS amplifier bias circuit below. Resistors RS and RD must set the drain current and drain voltage to the values in the table. The transistor parameters are also in the table. Perform the following calculations. Ignore λ. a. Calculate the value of RD. b. Calculate the magnitude of the overdrive voltage |VOV|. c. Calculate the source-to-gate voltage VSG. d. Calculate the value of RS.
The enhancement mode n-channel MOSFET M1 is biased at a de drain current ID of 50.0 μA in the saturation region with gate-source and drain-source voltages shown in Figure 3. Small-signal parameters and components for this device at the dc operating point are given below. β = 250 μA/V2 λ = 0 Cgs = 250 fF Cgd = 175fF Cgb = 40fF Cbd = Cbs = 800 fF Apply this data to calculate the gain-bandwidth product ωT in radians/second. Show your work and explain in detail all assumptions you make.